For me, Python has at some point or another been in each category, though at most two simultaneously.
And for those of us who do web development, "bread and butter" can easily include a half dozen languages or more. After leaving a project where I personally (no joke) used AS3, Awk, C, C++, C#, Java, JavaScript, Perl, PHP, Python, and SQL (sqlite, MySQL, and Postgres!) [1], my current position is just a trivially "polyglot" mix of C++ and Java desktop apps. Before that, I was constantly afraid that I'd forever be doomed to be a jack of all trades, master of none, but now the majority of my time is gobbled up by languages I don't like very much. Can't have it both ways...
[1] mostly by accident, as the powers that be could never make up their minds about what they actually wanted